SEOUL, Nov. 17 (Yonhap) -- Senior diplomats from South Korea, the United States and Japan will hold trilateral talks in Indonesia on Thursday to coordinate their joint strategy on the North Korean nuclear standoff, a Seoul official said.

The trilateral meeting, to be held later in the day ahead of the 18-nation East Asia Summit in Bali, will be led by Lim Sung-nam, Seoul's chief envoy to the stalled six-nation talks on ending the North's nuclear weapons programs, his Japanese counterpart Shinsuke Sugiyama and Kurt Campbell, assistant U.S. secretary of state for East Asian and Pacific affairs, the official said.

It will be the first meeting of senior officials from the three nations since July.

"The three diplomats are expected to jointly assess the outcome of last month's bilateral meeting in Geneva between the U.S. and North Korea, and exchange views on the direction of future dialogue," the official said on the condition of anonymity.

The Geneva talks between Washington and Pyongyang were aimed at reopening the stalled six-party talks. Both sides reported some progress after the Geneva meeting, but no agreement was reached to resume the broader talks.

The six-party talks, involving the two Koreas, the U.S., China, Russia and Japan, have been dormant since April 2009, when the North quit the negotiating table and then conducted its second nuclear test a month later.

Seoul and Washington said Pyongyang must first take concrete steps to show its sincerity before reconvening the talks, such as a monitored shutdown of its uranium enrichment plant. Pyongyang insists, however, that the talks should be resumed without any preconditions.

In the meantime, new U.S. Under Secretary of State Wendy Sherman will make a two-day visit to South Korea from Monday, foreign ministry spokesman Cho Byung-jae told reporters.

Sherman, who took office in October as the State Department's third-ranking official, will meet with senior South Korean officials and hold "overall and comprehensive discussions on bilateral relations, regional and global issues" during her trip, Cho said.